1. Field of the Invention
The present invention relates to a continuity checking device for a connector adapted to detect an abnormal condition that terminals in a connector have been incompletely inserted, by abutting an insertion checking pin against a flexible locking lance for locking the terminals, and more particularly to the connector continuity checking device which can detect the abnormal condition by visually observing the connector continuity checking device.
2. Description of the Related Art
FIG. 4 shows an example of a conventional connector continuity checking device.
This connector continuity checking device 70 is intended to check a state of continuity of terminals with electric wires which have been inserted and locked in a connector 71. The connector continuity checking device 70 includes a connector holding part 73 fixed to a frame 72, a checking part 74 arranged movably back and forth with respect to the connector holding part 73, and an operating lever 76 for actuating the checking part 74 by way of links 75.
The connector holding part 73 has a guide part 77 of a substantially columnar shape on which the connector 71 is adapted to be set from the above. The connector 71 is thus set in the connector holding part 73. The connector 71 includes a male type connector housing 78 made of synthetic resin and female type terminals with electric wires which have been inserted and locked inside the connector housing 78.
The checking part 74 includes a guide block 79 made of insulating resin in which a connector engaging chamber 80 is formed. A plurality of electrically conductive continuity checking pins (probe pins) corresponding to the terminals in the connector 71 are provided in the connector engaging chamber 80. The continuity checking pins (not shown) are connected to electric wires (not shown) and covered with a rear cover 81 at a side where the electric wires are drawn out. The guide block 79 is slidable back and forth along a pair of guide shafts (not shown), for example, in a horizontal direction inside the frame 72.
The operating lever 76 is bent in a substantially L-shape and rotatably connected to the frame 72 around shafts 82 at lower parts of its forward end portions. Upper parts of the forward end portions of the operating lever 76 are rotatably connected to backward ends of the links 75 around shafts 83. Forward ends of the links 75 are connected to side wall faces of the guide block 79 of the checking part 74 by means of shafts (bolts) 84. The shafts 83, 84 are passed through holes in the links 75 respectively so as to be slidable with respect to inner peripheries of the holes.
By rotating the operating lever 76 in a direction of an arrow a while the connector 71 is set on the connector holding part 73, the checking part 74 moves toward the connector 71 by way of the links 75, and a front half portion of the connector 71 is inserted into the connector engaging chamber 80. At the same time, the continuity checking pins (not shown) are brought into contact with the terminals (not shown) in the connector 71 respectively.
By rotating the operating lever 76 forward, the shafts 83 perform circular motions around the lower shafts 82 whereby the links 75 move forward, and the guide block 79 connected to the other shafts 84 moves forward.
The electric wires 85 from the connector 71 are connected to a continuity checking apparatus (a circuit integrating section) by way of a connector (not shown) which is connected to the other end of the electric wires 85. The electric wires (not shown) from the continuity checking pins are also connected to the continuity checking apparatus. Thus, the terminals in the connector 71 and the continuity checking pins constitute a closed circuit. When there exists a continuity between both the members, the continuity checking apparatus indicates an OK lamp, and when there is no continuity between them, the continuity checking apparatus indicates NG by means of a buzzer or a flashing light.
Meanwhile, in Japanese Patent Laid Open Publication No. 11-31570, there has been proposed a connector continuity checking device as shown in FIG. 5 which has a function of detecting an inserted state of the terminals in the connector, in addition to the function as the connector continuity checking device as described above.
This connector continuity checking device 94 includes a plurality of insertion checking pins 96 which are integrally formed with a holder 95 made of synthetic resin so as to project therefrom, a plurality of continuity checking pins 98 which are respectively inserted and fixed in cavities 97 in the holder 95, a pin block 99 made of synthetic resin and adapted to support the holder 95 slidably in back and forth directions, probe pins 101 having slidable portions 100 which are elastically in contact with rear ends of the continuity checking pins 98, and a guide block 103 having a connector engaging chamber 102 and mated with the pin block 99. One set of pins 104 is constituted by the holder 95, the insertion checking pins 96, and the continuity checking pins 98.
A connector 105 is inserted into the connector engaging chamber 102 by means of a similar mechanism to the conventional case. On this occasion, in case where one of the terminals is not completely inserted into a terminal containing chamber 107 as represented by a terminal 106 on a lower side, a flexible locking lance 108 of the connector housing is in contact with an outer peripheral face of the terminal 106 and deflected. Accordingly, a distal end of the insertion checking pin 96 is abutted against an end of the flexible locking lance 108, and the holder 95 retreats integrally with the insertion checking pin 96 and continuity checking pin 98. In short, the set pin 104 retreats, and the abnormal condition can be detected, because a contact between the continuity checking pin 98 and the terminal 106 is not attained.
In the above described conventional structure as shown in FIG. 5, defective continuity is indicated when the terminals 106 have not been completely inserted into the connector housing. However, in such an unusual case as an indication lamp is defective or an operator has missed the indication, it is concerned that quality of the check may not be assured. There is another problem that since the holder 95 slidably retreats in the pin block 99 when the insertion checking pin 96 is abutted against the flexible locking lance 108, the holder 95 may wear due to repeated use, resulting in bad motion or jerking.
Further, in Japanese Patent laid Open Publication No. 7-73949 (not shown), there is disclosed a structure in which an insertion checking pin abutted against a flexible locking lance which has been deflected retreats and shuts off a switching part, thereby causing a faulty electrical continuity and the NG continuity is indicated. In this structure too, there has been an anxiety that the switching part may wear and must be exchanged depending frequency of operation.
In view of the above described drawbacks, it is an object of the present invention to provide a continuity checking device for a connector which has a mechanism capable of reliably checking an abnormal condition in the event of an accident such as defect of an indication lamp or overlook of the indication, in which wear around the insertion checking pins with respect to the flexible locking lances and resulting breakdown, etc. can be prevented, and further, which has a simple structure and can be manufactured at a low cost.
In order to attain the above described object, there is provided, according to the present invention, a connector continuity checking device comprising a connector holding part in which a connector is set, a checking part including continuity checking pins capable of contacting with terminals of the connector, and insertion checking pins which can be inserted into spaces where flexible locking lances of the connector are deflected, the checking part being movable back and forth with respect to the connector holding part, and links which are connected to the checking part at its one end and connected to an operating lever at the other end, wherein the insertion checking pins are immovably fixed inside the checking part, whereby a gap is created between the checking part and the connector holding part, when the insertion checking pins are abutted against the flexible locking lances.
According to a second aspect of the present invention, each of the links includes a displacement absorbing mechanism.
According to a third aspect of the present invention, each of the links includes a pair of link plates and a link cover, and the displacement absorbing mechanism includes elongated holes respectively provided in the link plates in a longitudinal direction, and shafts of the link cover adapted to be slidably engaged in the elongated holes.
According to a fourth aspect of the present invention, the displacement absorbing mechanism includes an elastic member provided in the link cover, the link plates being urged in an expanding direction by the elastic member.
According to a fifth aspect of the present invention, biasing force of the elastic member is larger than resisting force for advancing the checking part.